Skeletal muscle involvement in tropical spastic paraparesis/HTLV‐1–associated myelopathy

Alberto Alain Gabbai, Clayton A. Wiley, Acary S.B. Oliveira, Ricardo Smith, Beny Schmidt, Joao A.M. Nóbrega, Jose O. Bordin, Gustavo C. Roman

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


The frequency of muscle involvement in TSP/HAM is not known, nor is the precise role that HTLV-1 and the diverse cytokines play in the genesis of HTLV-1-associated diseases. In order to better define the frequency and characteristics of the skeletal muscle involvement in TSP/HAM, we studied 11 affected patients. EMG was performed in 9 patients and muscle biopsy was performed in all 11. Muscle tissue was analyzed using: reverse transcriptase PCR for interleukin-1 in 8; PCR for HTLV-1 proviral DNA in 5; and electron microscopy for viral particles in 3. We found pathologic alterations in all 11 patients. Four patients (36%) had a neurogenic process, while a primary muscle involvement was observed in the rest (64%). Four patients (36%) had polymyositis, and 3 (27%) had a noninflammatory myopathy. Muscle weakness in the upper limbs was significantly associated with inflammation in the muscle biopsy. EMG was abnormal in only 2 of 9 patients. Reverse transcriptase PCR did not demonstrate message for interleukin-1 in any sample examined. PCR did identify HTLV-1 proviral DNA in the muscle of 3 patients. Retroviral-like particles were found, by EM, in only one biopsy. HTLV-1 may play an important role in the pathogenesis of the frequent myopathies associated with HAM/TSP.

Original languageEnglish (US)
Pages (from-to)923-930
Number of pages8
JournalMuscle & Nerve
Issue number8
StatePublished - Jan 1 1994


  • electron microscopy
  • HTLV-1
  • myopathy
  • PCR
  • polymyositis

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)


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